Machine for



A. L. HATFIELD.

Calcuiator. No. 11,726. Patented Sept. 26, 1854.

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UNITED srnrss PATENT orr on.

AARON L. HATFIELD, OF LEYVISBURG, PENNSYLVANIA.

MACHINE FOR ADDING NUMBERS.

Specification of Letters Patent No. 11,726, dated September 26, 1854. J-

To all whom it may concern:

Be it known that I, AARON L. HA'rrmLn, of Lewisburg, in the county ofUnion, State of Pennsylvania, have invent-ed a new and useful Instrumentfor Reckoning Figures.

The nature of my invention consists in providing a series oi circularmetallic disks having numbers stamped thereon, so arranged, inconnection with springs, that by the alternate movement of a lever, anynumber of figures, from 1 up to 10,000, or more, may be correctly andeasily added together before the eye.

To enable others skilled in the art to make and use my invention, 1 willproceed to describe its construction and operation, reference being hadto the annexed drawings forming part of this specification, in whichFigure 1 is a vertical view of one of my instruments. Figs. 2 and 3 arealso vertical views. Fig. 1 is a vertical section. Fig. 5 is a top viewof one o-t'the disks. Fig. 6 is a bottom View of the same. Fig. 7 is avertical view of the case with the disks removed. Fig. 8 is a bottomview of disk C.

Similar letters refer to like parts.

A, is the case; B, the outer disk and lining; C, the intermediate disk;D, the upper disk; E, the lower disk; F, center pivot; G,reckoning-lever; H, washer; a, fixed cam attached to the bottom side ofthe disk E; Z), stop on the outer disk B; 0, slots cut entirely throughthe intermediate disk 0; (Z, teeth sunk in the upper side of the disk D;6", points of reference to the disk; d, steady pins; f, pin in pivot; g,handle in the lever G; 9, slotcut through the lever G.

is is a spring-ratchet; 00, spring fastened on the lower side of thelining B; y, springratchet attached to the lining B.

The disk D has numbers upon its outer edge commencing from 1 and runningup to 100 in the manner indicated in various figures. The disk C hasnumbers upon its outer edge commencing at 100 and running by hundreds upto 10,000 or more. The disk B has numbers upon its outer edge commencingat 1 and running up to 100.

The disk B, C, D and the reckoning-lever G, are fastened together bymeans of a pin, f, passing through the pivot F, and the washer H. Thesteady pins cl pass up from the lower disk E, through the opening in thecenter of the disk G into corresponding holes in the disk D;consequently there are no ineans of turning the disk C except thetriotion consequent upon its being placed between the two disks D and E,while the disks D and E move simultaneously as if they were made in onepiece by means of the steady pins d.

Suppose now that the reckoning-lever G is turned against the stop I) asseen in Fig. 1, through the slot 9 may be read the figures 5,200 on thedisk C, and 6 on the disk D. Suppose now that it is desirable to add tothis amount 15; in order to do so the reckoning-lever G is turned aroundin the direction of the arrow until the slot arrives over the figures 15on the disk B. The position of the lever and slot is seen at Fig. 2. Thelever is now pushed back again to the stop 6, and the spring-ratchet 7ccatching in one of the sunken teeth on the disk D carries the disk Dwith it and the lever, and when the lever arrives against the stop Z)the correct sum will be observed on looking through the slot 9 as shownin Fig. 3, the amount now before the eye being 5 200 and 21.

On the lower side of the disk E sunken teeth 6 are cut around the outeredge as seen in Fig. 6. Into these teeth the springratchet 3 takes andprevents the disk E, and consequently the disk, D, from moving, whilethe reckoning-lever G is being turned in the direction 01": the arrow,but permits the turning of the disks E and D when the reckoning-lever Gis moved in the contrary direction. The disk C being pressed between thetwo disks D and E, would revolve with these disks, by reason of thefriction, were there no means to prevent it. To accomplish this the diskG is bent to ward its outer edge in the form seen in Fig. L; and throughthe bend thus made slots are cut entirely through, as seen at 0 in Fig.8. Into these slots the spring-lever m, Figs. 4 and 7, catches andprevents the disk C from revolving. In order, therefore, that the disk Cmay be moved at the proper time some means must be devised for releasingthe spring 00. This is done by the cam a, affixed tothe bot-tom of thedisk E. At every entire revolution of the disk E the cam a, comes aroundand striking the spring 00, as seen in Fig. 4, bears it down until thecam 64 has passed the spring 00, when the latter flies up again, andstops the disk, the movement of the disk C at this time is onlyequivalent to one notch, which exhibits a corresponding increase of 100in the figthe slots cut in the curve; the outer disk ures seen throughthe slot 9. Therefore as and lining B with springs w and y, the often as100 is reckoned by the disk D the disk E with its sunken teeth 0, cam aand disk 0 is moved forward one notch, and steady pins d, the wholebeing arranged 15 5 in this manner the correctness of the sums andcombined in the manner and for the reckoned is insured at the slot 9.purposes set forth, or, in any other manner Having thus described myinvention I substantially the same.

A. -L. HATFIELD. [L.s.]

claim The slotted reckoning-lever G with the Witnesses: 10spring-ratchet is attached; the disk D with H. P. SHELLER,

its sunken teeth; the curved disk C, With HENRY C. HIoKoK.

